Endoscopic surgical instruments are often preferred over traditional open surgical devices since a smaller incision, or incisions, associated with endoscopic surgical techniques tends to reduce the post-operative recovery time and complications. Consequently, significant development has gone into a range of endoscopic surgical instruments that are suitable for precise placement of a distal end effector at a desired surgical site through a cannula of a trocar. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.).
Endoscopic devices are passed through an access port, such as a trocar, to allow the distal end effector to engage tissue within a body cavity of a patient. The tissue can also be cut using a cutting element, such as a knife. Loading forces experienced by a shaft of the device as the end effector engages the tissue may cause the shaft to bend relative to the handle and to thus result in jamming or binding between components participating in distal advancement and proximal return of the cutting element. As a result, the cutting element can be prevented from being properly used to cut tissue. As another undesirable consequence, if the binding occurs during advancement or retraction of the cutting instrument, the device cannot be removed because the cutting element cannot be properly returned to its default position. The surgeon may be forced to open up the patient and manipulate the instrument, potentially causing serious harm to the patient.
Accordingly, there remains a need for methods and devices for preventing binding of components of a cutting assembly of a surgical device.